US scientists have unveiled details of new structure that could double the capacity of rechargeable lithium-ion batteries used in devices including laptops and mobile phones.

The technology is based on a new material for the positive electrode that comprises a nano-crystalline, layered-composite structure.

Researchers at the US Department of Energy's Argonne National Laboratory explained that the method uses a two-component " composite" structure.

An active component that provides for charge storage is embedded in an inactive component that stabilises the structure.

The new materials yielded "exceptionally high charge-storage capacities" greater than 250 mAh/g in recent tests, or more than twice the capacity of materials in conventional rechargeable lithium batteries.

Theories explaining the high capacity of the manganese-rich electrodes and their stability on charge/discharge cycling will be discussed at a meeting of The Electrochemical Society.

By focusing on manganese-rich systems instead of the more expensive cobalt and nickel versions of lithium batteries, overall battery cost is reduced, the researchers explained.